Australia is an island continent located in the Southern Hemisphere comprising the mainland and Tasmania. It was originally inhabited by indigenous Australians and later colonized by Britain in 1770. In 1901, the six colonies federated to form the Commonwealth of Australia. Australia has diverse landscapes ranging from deserts to tropical rainforests and the Great Barrier Reef. It has a strong economy and is known for its unique fauna like kangaroos and koalas as well as landmarks like Uluru and Sydney Opera House.